Rates of sexual victimization and perpetration among college students remain disturbingly high. Alcohol is present in a large proportion of these incidents and heavy drinking patterns have been associated with both victimization and perpetration. Much of what is known about alcohol and sexual aggression is based on studies of female victims. To date, a limited amount of naturalistic research has considered the impact of men's alcohol consumption on perpetration of sexual aggression. Two studies of men are proposed to address this gap. First, using a sample of college freshmen males (N = 1700) we will examine whether men's alcohol consumption prospectively predicts sexual aggression perpetration over the next two years of college. Next, using a subsample (N = 200), we will consider the daily or temporal relationship, over 8 weeks, between episodes of alcohol consumption and sexually aggressive behavior. We hypothesize that the alcohol-sexual aggression perpetration relationship is moderated by several individual differences variables, such as sex- related alcohol expectancies, hostility toward women, and behavioral self-control. These moderators will be considered both at the distal, prospective level and at the proximal, daily level. Findings from these studies will provide significant new knowledge about the role of alcohol in men's perpetration of sexual aggression, using innovative methods. Moreover, findings can aid in the development of efficacious sexual aggression prevention programs that target men's alcohol consumption.